Charge transfer and islands in metal halides-graphite intercalation compounds: New evidence from x-ray diffraction of intercalated Mn Cl2

Single crystal structure studies at room temperature have been made for the first stage Mn Cl₂ intercalated graphite. The nominal composition was C_5·6 Mn Cl_2·4, as deduced from chemical analyses and X-ray diffraction intensities. The data are in agreement with the island model, already proposed for Ni Cl₂ intercalation. From the decrease in C-C bond length and comparison with As F₅ compound, it is shown that the charge transfer is determined by chlorine in excess with respect to free metal halide.     

Mixed valence polyiodides from tetraphenyldithiapyranylidene: Crystalline structure and optical properties

Two conducting polyiodide salts have been obtained by direct oxidation of the donor DIPSØ₄ by iodine. These salts are characterized by X-ray diffraction, Raman and optical spectroscopy. The nature of iodine species is determined and the degree of charge transfer is evaluated.     

Experimental determination and modelization of a unique phase diagram: solid solutions of antiferromagnetic organometallic radical cation salts

The physical properties of paramagnetic Mo(V) organometallic radical cation salts, , are investigated through the study of two series of solid solutions incorporating two kinds of anions ( or ). The combination of EPR and X-ray diffraction is used to specify the nature of the structural phase transitions which occur in the paramagnetic phase and to determine the corresponding ( T , x ) phase diagrams. Finally, antiferromagnetic resonance is studied to probe the low temperature antiferromagnetic ground state. In the last part of the paper, the observed complex phase diagram is analyzed by considering a compressible model with at least two independent modes of compression. We conclude that the larger compressibilities are associated with the smaller anions. Received 5 August 1998     

From isocyanides to trichloropyruvamides: application to a new preparation of oxamide derivatives

Isocyanides react readily with trichloroacetic acid anhydride forming stable hydrates of trichloropyruvamides. These compounds are valuable intermediates for obtaining oxamides by reaction with TMSCl/NEt₃ followed by addition of an amine.